1. Field
Embodiments described herein generally relate to systems and methods for producing synthetic gas. More particularly, such embodiments relate to systems and methods for producing synthetic gas using low grade coal or other carbonaceous feedstocks.
2. Description of the Related Art
Clean coal technology using gasification is a promising alternative to meet the global energy demand. Most existing coal gasification processes perform best on high rank (bituminous) coals and petroleum refinery waste products, but these processes are inefficient, unreliable, and expensive to operate when processing low grade coal. Low grade coal reserves including low rank and high ash coal remain underutilized as energy sources despite being available in abundance. Coal gasification coupled with methanation and carbon dioxide management offer an environmentally sound energy source. Synthetic or substitute natural gas (“SNG”) can provide a reliable supply of fuel. SNG, with the right equipment, can be produced proximate to a coal source. SNG can be transported from a production location into an already existing natural gas pipeline infrastructure, which makes the production of SNG economical in areas where it would otherwise be too expensive to mine and transport low grade coal.
Typical problems with SNG production include high auxiliary power and process water requirements. The large quantities of power and water needed to run the SNG production system can greatly escalate the cost of production and limit where SNG generation systems can be deployed.
There is a need, therefore, for more efficient systems and methods for producing SNG from coal that reduce the requirements for outside power and water.